On Tue, 25 Mar 2014, Peter Münster wrote: > On Tue, Mar 25 2014, Alan Stern wrote: > > > Below is a patch you should apply to normal 3.14 (nothing reverted). > > Hi Alan, > > I've used 3.12.14, because the source-tree is already set up. I hope > that this is ok. Yes. > > For this test, plug some device you aren't going to use (the mouse, for > > example, if you will be at a VT console instead of a graphics console) > > into the rear port normally used by the mouse. Plug the keyboard and > > anything else into front ports -- no other devices should be attached > > to a rear port. > > > > Then you can force the test device to go into runtime suspend by typing > > this: > > > > echo auto >/sys/bus/usb/devices/4-2/power/control > > echo 0 >/sys/bus/usb/devices/4-2/bConfigurationValue > > > > (I believe 4-2 is the correct path for the rear port where you like to > > plug the mouse.) > > > > After 5 seconds or so, force the device to resume by typing: > > > > echo on >/sys/bus/usb/devices/4-2/power/control > > > > Let's see what shows up in the kernel log. With luck the resume will > > hang but the rest of your system will keep on running. > > No more mouse after the test, but the rest of the system works. > Please find attached the log (copied from /var/log/messages). > > Here my commands: > echo 8 >/proc/sys/kernel/printk > echo auto >/sys/bus/usb/devices/4-2/power/control > sleep 2 > echo 0 >/sys/bus/usb/devices/4-2/bConfigurationValue > sleep 10 > echo on >/sys/bus/usb/devices/4-2/power/control This was a good test. It clearly shows there's something wrong with the USB controller hardware. Maybe it simply can't handle global suspend. Please try running the test again. When it finishes, go to the /sys/kernel/debug/usb/ohci/0000:00:12.1/ directory and post a copy of the "registers" file. Check the contents of that file several times; in the line that says "hcca frame", the value should change over time. Does it? Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
